General Properties
Incoloy alloy 800 is a widely used material of construction for equipment that must have high strength and resist oxidation, carburization, and other harmful effects of high-temperature exposure. (For high temperature applications requiring optimum creep and rupture properties, Incoloy alloys 800H and 800HTare used).

Applications

Valves, fittings and other components exposed to corrosive attack from 1100 to 1800 deg F.

Chemical/petrochemcical processing

Steam generator tubing in nuclear power plants

Specifications

ASTM/ASTE……….. UNS N08800/N08810/ N008811

DIN…………………. . 1.4876, 1.4958, 1.4959

Corrosion Resistance

Alloys 800, 800H and 800HT have the same nickel, chromium, and iron contents and generally display similar corrosion resistance. Since alloys 800H and 800HT are used for their high-temperature strength, corrosive environments to which these alloys are exposed normally involve high temperature reactions such as oxidation and carburization

Workability

The hot forming range for alloys 800H and 800HT is 1600–2200°F (870–1200°C). Heavy forging should be done at temperatures down to 1850°F (1010°C) and light working can be accomplished down to 1600°F (870°C). No working should be done between 1200 to 1600°F (650–870°C). The rate of cooling following hot forming is not usually critical for these alloys with respect to thermal cracking. However, they are subject to some carbide precipitation in the 1000 to 1400°F (540–760°C) temperature range and should be rapidly cooled through that range when sensitization is a concern.

Weldability

Alloys 800H and 800HT have the same good weldability as alloy 800. Both are normally used for applications requiring high creep-rupture strength and should be joined with welding products that have suitable strength characteristics for the intended service temperatures.